RE: New 1100 mAh A123 available everywhere and no word here!  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic:
  Printable Version
       

All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> A123Racing Support >> RE: New 1100 mAh A123 available everywhere and no word here!
Page: <<   < prev  1 2 3 [4] 5 6 7   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: New 1100 mAh A123 available everywhere and no wo... - 12/17/2007 1:06:12 PM   
plasticman


 

Posts: 275
Joined: 6/8/2005
From: Xenia, OH, USA
Status: offline 		I found one of the tabs to fall off rather easy; this was out of three packs that I was building. I think what I will do is cover the tabs with electrical grade silicon. That should hopefully secure the tab and provide a little protection from vibration as my appliation is for a gas plane. I am using twin receiver packs with a Smart-Fly battshare for redundancy.

David


_____________________________

Plasticman

(in reply to dragon_no_fly)
       Post #: 76

RE: New 1100 mAh A123 available everywhere and no w... - 12/21/2007 11:17:00 PM   
AmateurE


 

Posts: 2
Joined: 10/21/2004
From: N, IL, USA
Status: offline 		I have to concur with others regarding the tabs falling off. Out of the 4 VPX packs, 3 cells had the tabs fall off in my hand. The other cell was firmly welded.

Bob

(in reply to plasticman)
       Post #: 77

RE: New 1100 mAh A123 available everywhere and no w... - 12/22/2007 1:15:06 AM   
thaus


 

Posts: 44
Joined: 11/25/2004
From: vero beach, FL, USA
Status: offline 		With tab failure this frequent, how can anyone chose these cells to power their receivers?

(in reply to AmateurE)
       Post #: 78

RE: New 1100 mAh A123 available everywhere and no w... - 12/22/2007 1:24:48 AM   
coro_sk


 

Posts: 18
Joined: 7/24/2007
From: , SLOVAKIA
Status: offline
quote:

ORIGINAL: AmateurE

I have to concur with others regarding the tabs falling off. Out of the 4 VPX packs, 3 cells had the tabs fall off in my hand. The other cell was firmly welded.

Bob

When using BEC, it seems to be a problem. I plan using the cells in miniEllipse which I love, the risk of crash is strongly not welcome..
I will backup receiver power, probably, even if I have no tabs to fall off my M1A cells.

Anyway, You can solder to those cells, there is no problem EXCEPT A RISK OF DAMAGE to cell..
You have to be really as quick as possible, I mean half of a second. Then cool the cell terminal by wet sponge, immediately.
If not succesfull, let it cool down and try again later, never try to repeat immediately..

(in reply to AmateurE)
       Post #: 79

RE: New 1100 mAh A123 available everywhere and no w... - 12/22/2007 2:42:42 PM   
everydayflyer



Posts: 854
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline
quote:

ORIGINAL: thaus

With tab failure this frequent, how can anyone chose these cells to power their receivers?



I have read post of $4000 plus aerial video Helies being crashed due to poor welds on LiPoly tabs so what else is new?

My record:

A123 Racing /DeWalt 2300 mAh cells.
4 cell from A123 Racing and one had one dab weld. All of the Dewalt cells ahve been fine.
I have built
5-- 4S packs
4- 4S packs
1 -6S pack
2-3S packs
Total of 48 DeWalt cells in packs plus I have on hand a 10 cell brick , a 4S group and a 2S group , all welds checked for a grand total 64 Dewalt / A123 Racing cells. I also have one DeWalt that is unopended so welds unknown.

Each cell has 4 welds one each end so 8X64=512 welds with one bad one.

I have built 4- 4S packs from the B&D VPX packs and all welds have been fine.

Charles




(in reply to thaus)
       Post #: 80

RE: New 1100 mAh A123 available everywhere and no w... - 12/23/2007 11:23:27 AM   
coro_sk


 

Posts: 18
Joined: 7/24/2007
From: , SLOVAKIA
Status: offline 		Right now I am curious whether the single post appeared yet, about A123 M1A cell failing with open circuit, was the function of internal fuse going to open circuit, or perhaps failed tab, hopefully? I would be glad if it would be just the tab falling off..

Anyway, I will backup receiver power in my full mould electric powered glider. But I will let it be in small foamies.

And in addition, few small diodes hooked to balance port, may help bridging the open cell. Motor must cutoff immediately, but receiver and servo power may run thru balance port, bypassing open circuited cell thru diode, and use power of remaining cells. Diodes will be added to Cellshield-like DIY device. It just have to be avoided to reverse connection (it would burn diodes immediately).
And I dont expect troubles with powering just the receiver by 2s pack, as the currents are small compared to what electric motor consumes - but with tabs secured, or wires soldered to cells.

(in reply to everydayflyer)
       Post #: 81

RE: New 1100 mAh A123 available everywhere and no w... - 12/23/2007 3:10:25 PM   
dick Hanson



Posts: 9733
Joined: 12/12/2001
From: slc, UT, USA
Status: offline 		For the truly faint of heart and naysayers
(oddly enough ,those who never use anything till it's obsolete )
We offer the attached help

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by dick Hanson -- 12/23/2007 3:11:50 PM >

_____________________________

I am watching you ----
Libby

(in reply to coro_sk)
       Post #: 82

RE: New 1100 mAh A123 available everywhere and no w... - 12/23/2007 3:47:50 PM   
Lormuhl


 

Posts: 59
Joined: 10/20/2006
From: Bothell, WA, USA
Status: offline 		Amen to that Dick. After following these 123 threads I had to build one pack and test them for myself. After much testing, to see it for myself I decided to convert. I have already converted my H9 Ultimate biplane, GP Ultimate, Aerowrks 90-120 Yak and soon will be converting my Aeroworks 100cc Yak to A123's. I have done away with my regs. Theses cells are fantastic. With all of the cells I have built so far, VPX packs and 2300's I have not experienced any bad welds to date.

(in reply to dick Hanson)
       Post #: 83

RE: New 1100 mAh A123 available everywhere and no w... - 12/23/2007 5:03:31 PM   
dick Hanson



Posts: 9733
Joined: 12/12/2001
From: slc, UT, USA
Status: offline 		Yeh - I beat the shi- out of my 2300s and the 1100 by using the 1100's in a big foamie -and ran em flat time after time after time and watched the voltage shifts balancing as recharge occurred on EACH cell (using CellPro 4 charger).
Funny thing --according to the charger and then the othe NON balancing charger - I did absolutely zero harm to the cells .
When I see comments about "excssive tab failure" - I can bet money - the writer has no experience whatsoever with these -or likely-- any cells.
Some hints for the totally uninitiated :
1. If you are going to build a pack - enlist the assistance of someone who has some experience in soldering wires to cells - these are all very easy to do but there are basics in doing ANY cell soldering
2 get a charger which does balance and displays each cell during charge and balance.
Tho this is not mandatory - it is awfully helpful in seeing what the heck actually occurs.
3. At the very least, get a inexpensive VOM (That's a Volt Ohm Meter) and read cell voltages
4. make a simple discharge device -from tail light bulbbs of'n an old Chev is fine (#1157) and wath voltage during discharge
good info - compare it with ANY/ALL other cells you use .
The A123 cells have a very flat discharge -read charts (If you understand what they represent ) and then see how your own setup compares . After all this is accomplished and absorbed --- Then publish comments about how well other cells compare to these, used for power and servo power.



Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by dick Hanson -- 12/23/2007 5:12:39 PM >

_____________________________

I am watching you ----
Libby

(in reply to Lormuhl)
       Post #: 84

RE: New 1100 mAh A123 available everywhere and no w... - 12/23/2007 5:51:13 PM   
Mr.Pibb


 

Posts: 59
Joined: 5/5/2006
From: Lewis Center, OH, USA
Status: offline 		My tab failure was NOT due to anything I did. It was broken straight out of the package. I've not had any fail after the fact.
I've soldered directly to the cells a few times with no problems (including the one that the tab had fallen off of).

(in reply to dick Hanson)
       Post #: 85

RE: New 1100 mAh A123 available everywhere and no w... - 12/23/2007 5:56:39 PM   
dick Hanson



Posts: 9733
Joined: 12/12/2001
From: slc, UT, USA
Status: offline 		good show!
I bet the cell also works as well as the others
Y/N?
These are tough little buggers .

_____________________________

I am watching you ----
Libby

(in reply to Mr.Pibb)
       Post #: 86

RE: New 1100 mAh A123 available everywhere and no w... - 12/24/2007 12:03:41 AM   
cyclops2


 

Posts: 1810
Joined: 12/23/2005
From: Frenchtown, NJ, USA
Status: offline

I switched from NIMH to DEWALT & B&D PVX. I never felt like I was risking anything just to fly. LIFE is good. Hey. Lithium Iron does mean LIFE.

I sold the 4 fire extingushers.

Rich


(in reply to dick Hanson)
       Post #: 87

RE: New 1100 mAh A123 available everywhere and no w... - 12/24/2007 4:06:09 AM   
AmateurE


 

Posts: 2
Joined: 10/21/2004
From: N, IL, USA
Status: offline 		Just wanted to say I think these cells are excellent in my planes. I have been making 3S2P packs out of old laptop batteries for a long time so a 4S A123 1100 is a lot lighter and offers huge power benefits. What's not to like. The tabs falling off is just something you're going to have to check when you build your packs. While in their original VPX holder, I doubt one would see any failures when used in its intended tool as there is no opportunity for the tabs to move. The 3 out of 4 VPX packs that lost the tab came off with barely a touch of a finger. If the weld is going to fail, I'm sure you'll see it when you repace the original wiring. No big deal as soldering is quite easy.

Bob

(in reply to cyclops2)
       Post #: 88

RE: New 1100 mAh A123 available everywhere and no w... - 12/24/2007 7:38:01 PM   
dirtybird


 

Posts: 2828
Joined: 1/25/2002
From: Mesa, AZ, USA
Status: online 		I made up a 4 cell VPX pack for an electric I am flying. I had been charging it with a lab power supply with 3A max output. I set it to max to get a quick charge and went inside to check the NFL scores. I came back 20 minutes later to discover all 4 cells had been distroyed. Apparently one cell reached its maximum and shorted. The rest then went sort of like dominoes.
The good news is they did not explode and burn my house down. The cells were warm but not hot.
From now on I will set the power supply voltage for 3.6 volts/cell.
I had made the 4c pack to replace a 3cell LIPO. It was way too much. I would have yanked the wings off that little airplane. I will replace it with a 3c unit.
Has anyone tried to charge a 3c pack from a 12v lead acid battery directly? It seems the voltage ought to be about right.

(in reply to AmateurE)
       Post #: 89

RE: New 1100 mAh A123 available everywhere and no w... - 12/24/2007 8:23:16 PM